Abstract: The invention relates to a process for the manufacture of photopolymer printing blocks, which are utilizable for producing printed matter by flexography, typography or dry offset, of the type including a stage for polymerizing areas by exposure to ultraviolet rays; a stage for engraving non-polymerized areas by immersion and brushing in an engraving bath contained in an engraving tank, the bath becoming loaded with dissolved particles or particles in suspension during the engraving stage; and a separation of the constituents of the engraving bath, with the liquid obtained at the time of separation being injected back into the engraving tank, characterized in that the separation consists of filtration, during which the particles are progressively eliminated. The invention also relates to an engraving device for carrying out the process.

Abstract: An etching device for preparing flexible blocks which can be used for printing in flexography, typography or dry offset generally includes an etching tank containing a bath (22) and brushes (3), a stirring and heating device, and an overfill system (20) for discharging the solution from the etching tank through an outlet duct (21) to a separation device. The separation device includes a reception vat (14) having an upper part which is equipped with a device (10) for separating the water and the polymer, and at least one filtering membrane (7).

Abstract: A process for manufacturing photopolymer blocks, which are first exposed to UVA radiation and mounted on printing cylinders to in combination form a printing sleeve for carrying out printing in flexography and in dry offset, includes a series of automated steps for manufacturing the printing sleeves. A device for implementing the process includes a series of stations, arranged in line, one after the other, including a storage magazine for receiving the exposed printing sleeves, a solvent-vapor lock, an etching device, a drying device and a storage station for receiving the completed printing sleeves.

Abstract: A process for making plates from a photopolymer sheet which has been pre-exposed to ultraviolet radiation for conversion into printing plates for flexography, letterpress or dry-offset printing, includes the steps of inserting the sheet into an apparatus, sensitive side facing upwards and at high speed, so that the sheet is received on an etching plane and beneath a set of brushes, and etching the sheet under forces resulting from alternating movement of the brushes and to-and-fro movement of the brushes in a horizontal direction perpendicular to the alternating movement of the brushes. The sheet is automatically held in position during etching. Also disclosed is an apparatus for implementing this process, allowing for very rapid etching.

Abstract: An automated process, and a device for implementing the process, for preparing a printing block from a photopolymer plate which has been previously exposed to ultraviolet radiation to convert it into a printing block for flexography or typography, or dry offset. The process includes at least the steps of lowering the plate with its sensitive face down into an etching vat, and then etching the plate by the resultant effect of a reciprocating horizontal movement of plane brushes and a to-and-fro movement of the etching vat in a horizontal direction perpendicular to that of the brushes, with the plate being held in place by gravity during the etching.

Abstract: In the developing of light sensitive plates, the plates are passed through a tank of developing liquid which is subject to ultrasonic waves to assist the developing action. The tank is preferably protected from the atmosphere to hinder degradation of the developing liquid.

Abstract: The present invention relates to a tank for the treatment of offset plates by ultrasounds. An elongated rectilinear passageway is limited by a lower wall constituted by a vat with a peripheral flange and by an upper wall constituted by an inverted vat with a peripheral flange, a seal incorporating an elastic lip being tightened between inlet and outlet openings, a bath reservoir being formed in one of the vats to contain an ultra-sound generator, so that the plates to be treated, propelled by pairs of rollers, pass through the developer bath whose volume is minimum, in a straight line.